Slip-frequency type and flux-feedback type vector controls in discrete-time system

In this paper, we evaluate the difference between the slip-frequency type and the flux-feedback type in discrete time. Both vector control systems in discrete time, designed equivalently in continuous time, have different discretization errors. In a large sampling time region, the slip-frequency type (using the induction motor rotor-flux frame model) is less influenced by the discretization error than the flux-feedback type (using the stator frame model). In this sense, the slip-frequency type is superior to the flux-feedback type, but the stator frame model is linear and the rotor-flux frame model is nonlinear. With the flux-feedback type using the stator frame, it is easier to design the controller and the observer. Therefore, we believe that the vector controller and the observer should be designed using the stator frame model and that, after it is transformed to the rotor-flux frame model, it should be implemented